Search results for "abstract"
showing 10 items of 1959 documents
Sectors on sectors (SonS): A new hierarchical clustering visualization tool
2011
Clustering techniques have been widely applied to extract information from high-dimensional data structures in the last few years. Graphs are especially relevant for clustering, but many graphs associated with hierarchical clustering do not give any information about the values of the centroids' attributes and the relationships among them. In this paper, we propose a new visualization approach for hierarchical cluster analysis in which the above-mentioned information is available. The method is based on pie charts. The pie charts are divided into several pie segments or sectors corresponding to each cluster. The radius of each pie segment is proportional to the number of patterns included i…
Research opportunities in performance measurement in public utilities regulation
2015
Purpose – The purpose of this paper is to propose a method to choose a set of scientific articles about performance measurement in public utilities regulation. The method is designed to identify references with high academic relevance in databases accessed via the internet, and, through these articles, to perform a mapping of these publications and conduct a systemic analysis. Design/methodology/approach – The study is characterized as exploratory and descriptive with a qualitative and quantitative approach. Incorporates an inductive logic, and draws on primary and secondary data sources. The research involves the application of a technical procedure for selection and study of selected art…
Adding Synthetic Detail to Natural Terrain Using a Wavelet Approach
2002
Terrain representation is a basic topic in the field of interactive graphics. The amount of data required for good quality terrain representation offers an important challenge to developers of such systems. For users of these applications the accuracy of geographical data is less important than their natural visual appearance. This makes it possible to mantain a limited geographical data base for the system and to extend it generating synthetic data.In this paper we combine fractal and wavelet theories to provide extra data which keeps the natural essence of actual information available. The new levels of detail(LOD) for the terrain are obtained applying an inverse Wavelet Transform (WT) to…
Coarse to fine : toward an intelligent 3D acquisition system
2015
International audience; The 3D acquisition-compression-processing chain is , most of the time , sequenced into independent stages. As resulting , a large amount of 3D points are acquired whatever the geometry of the object and the processing to be done in further steps. It appears , particularly in mechanical part 3D modeling and in CAD , that the acquisition of such an amount of data is not always mandatory. We propose a method aiming at minimizing the number of 3D points to be acquired with respect to the local geometry of the part and therefore to compress the cloud of points during the acquisition stage. The method we propose is based on a new coarse to fine approach in which from a coa…
Gaussian Process Regression (GPR) Representation in Predictive Model Markup Language (PMML)
2017
International audience; This paper describes Gaussian process regression (GPR) models presented in predictive model markup language (PMML). PMML is an extensible-markup-language (XML) -based standard language used to represent data-mining and predictive analytic models, as well as pre- and post-processed data. The previous PMML version, PMML 4.2, did not provide capabilities for representing probabilistic (stochastic) machine-learning algorithms that are widely used for constructing predictive models taking the associated uncertainties into consideration. The newly released PMML version 4.3, which includes the GPR model, provides new features: confidence bounds and distribution for the pred…
A Formal Semantics and a Client Synthesis for a BPEL Service
2008
A complex Web service described with languages like BPEL4WS, consists of an executable process and its observable behaviour (called an abstract process) based on the messages exchanged with the client. The abstract process behaviour is non deterministic due to the internal choices during the service execution. Furthermore the specification often includes timing constraints which must be taken into account by the client. Thus given a service specification, we identify the synthesis of a client as a key issue for the development of Web services. To this end, we propose an approach based on (dense) timed automata to first describe the observable service behaviour and then to build correct inte…
Knowledge-based verification of concatenative programming patterns inspired by natural language for resource-constrained embedded devices
2020
We propose a methodology to verify applications developed following programming patterns inspired by natural language that interact with physical environments and run on resource-constrained interconnected devices. Natural language patterns allow for the reduction of intermediate abstraction layers to map physical domain concepts into executable code avoiding the recourse to ontologies, which would need to be shared, kept up to date, and synchronized across a set of devices. Moreover, the computational paradigm we use for effective distributed execution of symbolic code on resource-constrained devices encourages the adoption of such patterns. The methodology is supported by a rule-based sys…
El panel de loterías como tarea no paramétrica para la obtención de la actitud frente al riesgo
2012
In this paper, we propose a simple task for eliciting attitudes toward risky choice, the Sabater-Grande and Georgantzís (SGG) lottery-panel task, which consists in a series of lotteries constructed to compensate riskier options with higher risk-return trade-offs. Using Principal Component Analysis technique, we show that the SGG lotterypanel task is capable of capturing two dimensions of individual risky decision making: subjects’ average willingness to choose risky projects and their sensitivity towards variations in the return to risk. We report results from a large dataset obtained from the implementation of the SGG lottery-panel task and discuss regularities and the desirability of its …
Publication Data Integration as a Tool for Excellence-Based Research Analysis at the University of Latvia
2017
The evaluation of research results can be carried out with different purposes aligned with strategic goals of an institution, for example, to decide upon distribution of research funding or to recruit or promote employees of an institution involved in research. Whereas quantitative measures such as number of scientific papers or number of scientific staff are commonly used for such evaluation, the strategy of the institution can be set to achieve ambitious scientific goals. Therefore, a question arises as to how more quality oriented aspects of the research outcomes should be measured. To supply an appropriate dataset for evaluation of both types of metrics, a suitable framework should be p…
Artificial mosaics
2005
Art often provides valuable insight that can be applied to technological innovations, especially in the fields of image processing and computer graphics. In this paper we present a method to transform a raster input image into a good-quality mosaic: an “artificial mosaic.” The creation of mosaics of artistic quality is challenging because the tiles that compose a mosaic, typically small polygons, must be packed tightly and yet must follow and emphasize orientations chosen by the artist. The proposed method can reproduce the colors of the original image and emphasize relevant boundaries by placing tiles along edge directions. No user intervention is needed to detect the boundaries: they are …